Hong Kong’s transport chief has said that late-night aircraft noise over Tung Chung is within acceptable limits in terms of risks to residents’ health.

Lawmaker Chan Hok-fung relayed concerns from residents during a legislative Q&A on Wednesday. He said that the issue “has been aggravated significantly,” since the operating hours of the South Runway were extended to 2am in August last year.

His requests for the utilisation rate of the runway during midnight and 2am were not met by Secretary for Transport and Logistics Mable Chan. However, the minister said that the Airport Authority had conducted health impact assessments with regard to noise.

“The assessment indicates that both short-term and long-term potential health risks resulting from the operation of the 3RS [Three Runway System] are within acceptable levels,” she said.

The Aviation Environmental Federation, a UK-based non-profit, says high levels of aviation noise can lead to chronic sleep disturbance and long-term annoyance.

The World Health Organization (WHO) recommends that the annual average outdoor noise level for aircraft, across 24 hours, remains below 45 decibels. The WHO uses a Day-Evening-Night level metric, taking account of quiet and loud moments throughout a year, whilst penalising night-time noise before averaging them out to a single figure.

In environmental impact assessments, Hong Kong uses the Noise Exposure Forecast (NEF) 25 contour, under which the day-night average sound level of aircraft should be kept at around 55 to 60 decibels.

Hong Kong’s Civil Aviation Department monitors aircraft noise by tracking the peak instantaneous noise level of individual flights passing overhead, rather than a continuous annual average. It then publishes the percentage of total flights which hit certain decibel brackets.

In the 12 months leading up to March 31 this year, 91.49 per cent of flights over Tung Chung emitted noise under 65 decibels – the rest exceeded the limit.

Mitigation measures

The transport chief said on Wednesday that a number of aircraft noise mitigation measures had been rolled out and aviation technology was improving to dampen engine sound.

“Relevant measures include control at source by prohibiting/restricting aircraft with higher noise levels from operating in Hong Kong, and reducing the number of flights overflying densely populated areas at night when weather and safety conditions permit, such as arranging arrival aircraft to land from the southwest over the water, thereby mitigating the noise impact on residents living in the vicinity of the airport,” she said.

“While consolidating and enhancing Hong Kong’s position as an international aviation hub, the Government will continue to balance community well-being and environmental benefits, proactively promoting the synergistic development of the aviation industry and the environment to achieve high-quality and sustainable growth,” she added.

Hongkongers may complain about aircraft noise by contacting the Civil Aviation Department hotline on 2769 6969 or emailing aircraftnoise@cad.gov.hk.

Allowing vehicles from Guangdong province to enter Hong Kong’s South Lantau must be approached with “caution,” Hong Kong’s transport chief has told lawmakers.

At a Legislative Council meeting on Wednesday, Secretary for Transport and Logistics Mable Chan said that authorities would have to consult local residents and the district council, citing recent cases of vehicles from Guangdong illegally entering the restricted scenic roads on rural South Lantau.

Addressing a question from lawmaker and rural leader Kenneth Lau, Chan said: “Regarding reviews of quotas and other potential improvements for self-drive tours on Lantau going forward, we will cautiously and carefully monitor the situation. We will also consult and explore options with local residents and the Islands District Council.”

Vehicles under the Southbound Travel for Guangdong Vehicles scheme have been operating smoothly, and testing centres in Guangdong have provided drivers with information on Hong Kong’s traffic rules, she added.

Under the southbound travel scheme, which took effect in December, up to 100 private cars from Guangdong province are permitted daily to drive into Hong Kong’s urban areas via the Hong Kong-Zhuhai-Macao Bridge and stay for a maximum of three days.

The transport minister had previously touted the scheme as a boon for Hong Kong’s economy, driving tourism and trade while enhancing “integration” for citizens in both regions.

The government launched the Driving on Lantau Island Scheme in 2016, allowing a daily quota of 25 private cars to access closed roads to Ngong Ping, Tai O, Cheung Sha and Mui Wo on weekdays. The second phase was launched in 2022, with the daily quota increased from 25 to 50.

Under the scheme, some 12,000 quotas are available for allocation each year, with all of them filled.

Citing official figures, Chan said that the Transport Department received about 84,000 applications in 2023 and about 30,000 in each of the subsequent two years. She attributed the high number from three years ago to pandemic-related travel restrictions that limited residents to local tourism.

Responding to a suggestion by lawmaker Chan Hok-fung to extend South Lantau permits from one day to two or three days, the transport minister said the authorities would look into extending the permit period to include weekends.

But she added that any quota extensions must balance tourism development and local residents’ traffic concerns.